Tired?by Ethan Vye, Newark, DEAttention, teenagers! Do you feel sleepy when you're at school? Do you stay up too late at night, even when you know that you won't be able to get up in the morning? If your answer is "yes," you're not alone, and it may not be totally your fault. According to researchers at the Minnesota Regional Sleep Disorders Center, teenagers often become victims of their uncontrollable biological clocks.Puberty causes many changes. Studies have determined that one change is in a person's biological clock. Your biological clock tells you when to fall asleep and when to wake up. It also determines how alert you are during certain times of the day. The saying " Early to bed, early to rise" just doesn't work any longer. Now your body naturally wants to go to sleep late and get up late. This is hard when you have to get up at 6 a.m. for school. Most teenagers only get about three-quarters of the sleep they need. This lack of sleep causes a condition called sleep deprivation. How does this affect you at school? Sleep deprivation causes shortened attention span, depression and irritability. No wonder it's sometimes difficult for us to stay awake and be efficient learners! Since teens can't control their biological clock, how can this complicated problem be solved?One solution being tried in Minnesota schools is a later starting time for teens. Instead of starting school at 7: 30 a.m., they begin at 8: 30 a.m. This may not seem like much of a difference, but almost all of the schools that are trying this have seen dramatic improvements in student achievement and behavior. Seems good, right? Problem solved? Wrong. A later starting time equals a later ending time, which can cause problems with transportation, homework time, work scheduling and extracurricular activities.I am in favor of a later starting time. I know that I don't have to worry about all the problems associated with it, but I really think that I would benefit greatly by getting an extra hour of sleep. So would the 20% of all high school students who fall asleep every day in school. I agree that making this change wouldn't be easy, but, with careful planning, I think it could be the best option and solution to teenagers' uncontrollable biological clock. tf